At least three people, including a leader of the Jamiat Ulema-i-Islam-Fazl (JUI-F), were killed and more than a dozen others injured in an explosion that rocked the Chaman area of Balochistan's Qilla Abdullah District, Chaman Assistant Commissioner Yasir Dashti said.
According to police officials, the bomb was an improvised explosive device (IED) which was planted in a motorcycle parked on the roadside.
The explosion initially left Maulana Muhammad Hanif, a central leader of the JUI-F, critically injured. He was being shifted to Quetta when he succumbed to his injuries on the way to the hospital, Dashti said.
Police said Hanif was the target of the attack.
The blast occurred on Taj Road in Chaman, which is located just kilometres away from the country's border with Afghanistan, and shattered windows in nearby buildings.
The dead include a 12-year-old child, Chaman District Police Officer Shaukat Mohmand told DawnNewsTV.
The injured were shifted to Civil Hospital Chaman, where an emergency was declared.
Chaman is considered a sensitive town in Balochistan as it shares a border with Afghanistan's volatile Kandahar province.
The blast took place amid heightened security in the area due to a presidential vote being held across the border in Afghanistan.
No group immediately claimed responsibility for the blast.
Prime Minister Imran Khan strongly condemned the incident and expressed profound sorrow and regret over the loss of precious lives, including the JUI-F leader.
The premier extended his heartfelt condolences to the heirs of the deceased and prayed that they find the strength to bear the irreparable loss.
He also directed authorities to provide the best possible medical treatment to all those injured.
JUI-F leaders have been targeted in attacks in Balochistan in the past as well.
In May 2017, JUI-F leader and former Senate deputy chairman Maulana Abdul Ghafoor Haideri had suffered injuries in a suicide attack on his convoy in the Mastung area. At least 28 people were killed in the attack and 39 others were injured.
In 2014, the party chief Maulana Fazlur Rehman had survived a suicide attack in Quetta when he was returning after addressing a public meeting at Sadiq Shaheed Ground.